Concept explainers
Some researchers claim that herbal supplements improve human memory. To test this claim, a researcher selects a sample of n = 25 college students. Each student is given herbal supplements daily for 6 weeks and then all the participants are given a standardized memory test. For the population, scores on the tests are
You will be using the z-score statistic instead of the t test to test the hypotheses because________________
Step by stepSolved in 2 steps with 2 images
- A substance abuse counselor wants to demonstrate the effect of situational stress on alcohol cravings. He recruits two groups of men who are similar in respect to history of alcohol use and demographic variables. He divides them in to two groups. In one group(n=11), the men are exposed to a stressful situation and then asked to complete a measure rating their alcohol cravings on a scale from 0-10, where 0 representsno cravings and 10 represents intense cravings. In the second group (n=10), the men are exposed to a neutral situation and asked to complete the same measure. What test and graph should I create to find out if a stressful situation result in more intense alcohol cravings than a non-stressful situation?arrow_forwardA physical therapist wanted to know whether the mean step pulse of men was less than the mean step pulse of women. She randomly selected 54 men and 70 women to participate in the study. Each subject was required to step up and down a 6-inch platform. The pulse of each subject was then recorded. The following results were obtained. Two sample T for Men vs Women N Mean StDev SE Mean Men Women 98% CI for mu Men - mu Women (- 12.20, - 1.00) T-Test mu Men = mu Women (vs H2 O C. Ho: H1 = H2; Ha: H1 #H2 (b) Identify the P-value and state the researcher's conclusion if the level of significance was a = 0.01. What is the P-value? P-value =arrow_forwardTwo separate samples receive two different treatments. The first treatment group (N = 9) has a mean of 50 with SS = 710. The second treatment group (N = 6) has a mean of 60 with SS = 460. Is the second treatment group significantly larger than the first? What is the effect size?arrow_forward
- Consider the information above and in question 1. It is conjectured that the mean number of people attending all 2017 Veterans Day celebrations is 145, and of interest is to test this conjecture versus the alternative that the mean number of people attending all 2017 Veterans Day celebrations is different from 145 people To test the hypothesis, a simple random sample of 41 Veterans Day celebrations was selected and the number of people attending each was recorded. The mean number of people attending for this sample of 41 celebrations was 157, with a standard deviation of 23 people. The distribution of the data was bimodal. If appropriate, use this information to test the hypotheses stated in question 3 at the a= .05 level of significance. 4 Are the assumptions met? Yes, because there is a simple random sample Yes, because there is a simple random sample and the population is normally distributed Yes, because there is a simple random sample and the sample size is large enough for the…arrow_forwardThe following information is available for two samples selected from independent normally distributed populations. Population A: n1=30 S2/1=25 Population B: n2=30 S2/2=36 a. Which sample variance do you place in the numerator of FSTAT? b. What is the value of FSTAT?arrow_forwardQUESTION 8 You are interested in seeing whether emotions impact decision making. You have three groups--a happy group, a sad group, and a neutral group. For the happy group there are 5 participants and the mean risky decision making score 5.0 with a standard deviation of 0.7. For the sad group there are 5 participants and the mean risky decision making score 5.4 with a standard deviation of 1.1. For the neutral group there are 5 participants and the mean risky decision making score 5.8 with a standard deviation of 2.8. The sum of squares between samples is equal to 1.6. The sum of squares within samples is equal to 38.0. What is the degrees of freedom total? Please do the calculations on the handout provided.arrow_forward
- Consider the information above and in question 1. It is conjectured that the mean number of people attending all 2017 Veterans Day celebrations is 145, and of interest is to test this conjecture versus the alternative that the mean number of people attending all 2017 Veterans Day celebrations is different from 145 people To test the hypothesis, a simple random sample of 41 Veterans Day celebrations was selected and the number of people attending each was recorded. The mean number of people attending for this sample of 41 celebrations was 157, with a standard deviation of 23 people. The distribution of the data was bimodal. If appropriate, use this information to test the hypotheses stated in question 3 at the a = .05 level of significance. O 7 What is the p-value? 0.05 p-value < 0.10 0.0005 0.03 0.001 < p-value < 0.002 0.0008 4-arrow_forwardA two-way ANOVA experiment with interaction was conducted. Factor A had three levels (columns), factor B had five levels (rows), and six observations were obtained for each combination. Assume normality in the underlying populations. The results include the following sum of squares terms: SST=1542 SSA= 1042 SSB = 358 SSAB = 39 a. Construct an ANOVA table. (Round "MS" to 4 decimal places and "F" to 3 decimal places.) ANOVA Source of Variation Rows Columns Interaction Error Total SS 0 df Answer is not complete. 0 MS F p- value 0.000 0.000 0.002arrow_forwardQuestion #3 Samples of body temperatures were collected for a group of women and a group of men. The summary statistics are given below: Women:n1 = 15 sample mean = 98.38 ̊F s1 = 0.45 ̊F Men:n2= 91 sample mean= 98.17 ̊F s2 = 0.65 ̊F 1. Use a 0.01 significance level to test the claim that women and men have different mean body temperatures using the p value method. Show all the steps of your hypothesis test including the p value: initial conclusion: a final conclusion about the original claim:arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman